Messages in this thread | | | Date | Sun, 15 Apr 2012 18:16:31 +0300 | From | Avi Kivity <> | Subject | Re: [PATCH v2 10/16] KVM: MMU: fask check whether page is writable |
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On 04/13/2012 01:14 PM, Xiao Guangrong wrote: > Using bit 1 (PTE_LIST_WP_BIT) in rmap store the write-protect status > to avoid unnecessary shadow page walking > > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > --- > arch/x86/kvm/mmu.c | 40 ++++++++++++++++++++++++++++++++++------ > 1 files changed, 34 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 0c6e92d..8b71908 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -796,7 +796,9 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn) > return level - 1; > } > > -#define PTE_LIST_DESC (0x1ull) > +#define PTE_LIST_DESC_BIT 0 > +#define PTE_LIST_WP_BIT 1 > +#define PTE_LIST_DESC (1 << PTE_LIST_DESC_BIT) > #define PTE_LIST_FLAG_MASK (0x3ull) > > static void > @@ -1067,6 +1069,12 @@ static bool rmap_can_add(struct kvm_vcpu *vcpu) > return mmu_memory_cache_free_objects(cache); > } > > +static void host_page_write_protect(u64 *spte, unsigned long *rmapp) > +{ > + if (!(*spte & SPTE_HOST_WRITEABLE)) > + __test_and_set_bit(PTE_LIST_WP_BIT, rmapp); > +} >
Why is this needed, in addition to spte.SPTE_WRITE_PROTECT?
-- error compiling committee.c: too many arguments to function
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